1. Field of the Disclosure
The present invention relates to an optical fiber.
2. Description of the Related Art
Along with the recent tremendous growth in Internet traffic, the power of the light transmitted through a single optical fiber has also increased; therefore, nonlinear optical phenomena in optical fibers and fiber fuses have become major problems. An effective solution to the above problems is to increase the effective core area (Aeff) of the optical fiber. However, when performing single-mode transmission at a communication waveband by using a conventional solid optical fiber that has an increased effective core area, a problem occurs in that macrobending losses and microbending losses are increased. A microbending loss is defined as an increase in the transmission loss due to a minute bend in an optical fiber that occurs when lateral pressure is applied to the optical fiber.
To decrease the macrobending loss that occurs when single-mode transmission is performed with the effective core area being increased, methods are proposed that optimize refractive index profiles. For example, an optical fiber is proposed in the “Trench-Assisted Profiles for Large-Effective-Area Single-Mode Fibers,” ECOC2008, Mo.4.B.1, by Marianne Bigot-Astruc, Frans Gooijer, Nelly Montaigne, Pierre Sillard (hereinafter to be referred to as Nonpatent Reference 1), that has an effective core area that is increased to 120 μm2 by optimizing the trench-type refractive index profile. Moreover, according to “OSNR-Enhancing Pure-Silica-Core Fiber with Large Effective Area and Low Attenuation,” OFC/NFOEC2010, OTuI2, by Yoshinori Yamamoto, Masaaki Hirano, Kazuya Kuwahara, Takashi Sasaki (hereinafter to be referred to as Nonpatent Reference 2), the effective core area is increased to 134 μm2 by optimizing a W-shaped refractive index profile.